Tetradentate platinum (II) and palladium (II) complexes and octahedral iridium complexes employing azepine functional groups and their analogues

ABSTRACT

Platinum (II) and palladium (II) complexes of Formulas A and B and iridium (III) complexes of Formula C having azepine functional groups and their analogues as emitters for full color displays and lighting applications.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/625,082, filed on Jun. 16, 2017, now U.S. Pat. No. 10,177,323, whichclaims the benefit of U.S. Application Ser. Nos. 62/377,883 and62/377,884, both filed on Aug. 22, 2016, all of which are incorporatedherein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to platinum (II), palladium (II), andiridium (III) complexes having azepine functional groups and theiranalogues as emitters for organic light emitting diodes (OLEDs).

BACKGROUND

Compounds capable of absorbing and/or emitting light can be ideallysuited for use in a wide variety of optical and electroluminescentdevices, including, for example, photo-absorbing devices such as solar-and photo-sensitive devices, OLEDs, and photo-emitting devices. Muchresearch has been devoted to the discovery and optimization of organicand organometallic materials for using in optical and electroluminescentdevices. Generally, research in this area aims to accomplish a number ofgoals, including improvements in absorption and emission efficiency andimprovements in the stability of devices, as well as improvements inprocessing ability.

Despite significant advances in research devoted to optical andelectro-optical materials (e.g., red and green phosphorescentorganometallic materials are commercially available and have been usedas phosphors in OLEDs, lighting and advanced displays), many currentlyavailable materials exhibit a number of disadvantages, including poorprocessing ability, inefficient emission or absorption, and less thanideal stability, among others.

SUMMARY

Complexes disclosed herein include platinum, palladium, and iridiumcomplexes that are useful for full color displays and lightingapplications. Provided herein are complexes of formulas A, B, and C:

where the constituent variables are defined herein.

Light emitting devices including complexes represented by Formulas A, B,and C are described. Examples of light emitting devices include OLEDs(e.g., phosphorescent OLED devices), photovoltaic devices, luminescentdisplay devices, and the like.

Variations, modifications, and enhancements of the described embodimentsand other embodiments can be made based on what is described andillustrated. In addition, one or more features of one or moreembodiments may be combined. The details of one or more implementationsand various features and aspects are set forth in the accompanyingdrawings, the description, and the claims below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a cross section of an exemplary OLED.

DETAILED DESCRIPTION

Platinum (II), palladium(II), and iridium (III) complexes of the presentdisclosure provide improvements in color purity, enhanced operationalstability, and eliminate potential intermolecular interactions, makingthem suitable for full color displays and lighting applications.

This disclosure relates to the complexes represented by Formulas A, B,and C, each of which is described below. Complexes of Formula A arerepresented as:

where:

M represents Pt²⁺ or Pd²⁺;

Ar¹, Ar², Ar³, Ar⁴, and Ar⁵ each independently represents an aryl orheteroaryl;

R¹, R², R³, R⁴, and R⁵ each independently represents hydrogen, halogen,hydroxyl, nitro, thiol, or substituted or unsubstituted C₁-C₄ alkyl,alkoxy, amino, or aryl;

each n is 0, 1, 2, 3, 4, or 5, valency permitting;

Y^(1a), Y^(1b), Y^(1c), Y^(1d), Y^(1d), Y^(1e), Y^(2a), Y^(2b), Y^(2c),Y^(2d), Y^(2e), Y^(3a), Y^(3b), Y^(3c), Y^(3d), Y^(3e), Y^(4a), Y^(4b),Y^(4c), Y^(4d), Y^(4e), Y^(5a), Y^(5b), Y^(5c), Y^(5d), and Y^(5e) eachindependently represents C, N, Si, O, or S;

Y^(1f), Y^(2f), and Y^(3f), valency permitting, each independentlyrepresents N, P, N═O, P═O, NR, PR, CR, SiR, CR₂, SiR₂, O, or S;

at least one of X¹ and X² independently represents one of the followingmoieties:

and

the other of X¹ and X², if not one of the moieties above, isindependently present or absent, and each X¹ and X² presentindependently represents a single bond, NR, PR, BR, CRR′, SiRR′, O, S,S═O, O═S═O, Se, Se═O, or O═Se═O;

each of R and R′ is independently present or absent, and each R and R′present independently represents substituted or unsubstituted C₁-C₄alkyl, aryl, or heteroaryl;

R⁸, R⁹, R¹⁰, and R¹¹ each independently represents hydrogen, halogen,hydroxyl, nitro, thiol, or substituted or unsubstituted C₁-C₄ alkyl,alkoxy, amino, or aryl;

each of L¹, L², L³, and L⁴ is independently present or absent, and eachL¹, L², L³, and L⁴ present represents a linking atom or linking group.

The linking atom can optionally, if valency permits, have other chemicalmoieties attached. Suitable chemical moieties include hydroxy, amide,thiol, or substituted or unsubstituted alkyl, alkoxy, alkenyl, alkynyl,amino, aryl, heteroaryl, cycloalkyl, and heterocyclyl.

Embodiments of Formula A include:

where:

U represents O, S, NR, or PR;

U¹ represents N, P, As, B, NO, PO, or AsO;

Z represents O, S, SO, S(O)₂, NR, PR, CR₂, SiR₂, or BR;

Z¹ represents C or N;

Z² represents C or N, and

each R independently represents substituted or unsubstituted C₁-C₄alkyl, aryl, or heteroaryl.

Complexes of Formula B are represented as:

where:

Ar¹, Ar², Ar³, Ar⁴, and Ar⁵ each independently represents an aryl orheteroaryl;

M represents Pt²⁺ or Pd²⁺;

R¹, R², R³, R⁴, and R⁵ each independently represents hydrogen, halogen,hydroxyl, nitro, thiol, or substituted or unsubstituted C₁-C₄ alkyl,alkoxy, amino, or aryl;

each n is independently 0, 1, 2, 3, 4, or 5, valency permitting;

Y^(1a), Y^(1b), Y^(1c), Y^(1d), Y^(1e), Y^(2a), Y^(2b), Y^(2c), Y^(2d),Y^(2e), Y^(3a), Y^(3b), Y^(3c), Y^(3d), Y^(3e) Y^(4a), Y^(4b), Y^(4c),Y^(4d), Y^(4e) Y^(5a), Y^(5b), Y^(5c), Y^(5d), and Y^(5e) eachindependently represents C, N, Si, O, or S;

Y^(1f), and Y^(3f), valency permitting, each independently represents N,P, N═O, P═O, NR, PR, CR, SiR, CR₂, SiR₂O, or S; at least one of X¹ andX² independently represents the following moieties:

and the other X¹ and X², if not one of the moieties above, isindependently present or absent, and each X¹ and X² presentindependently represents a single bond, NR, PR, BR, CRR′, SiRR′, O, S,S═O, O═S═O, Se, Se═O, or O═Se═O;

each of R and R′ is independently present or absent, and each R and R′present represents substituted or unsubstituted C₁-C₄ alkyl, aryl orheteroaryl;

R⁸, R⁹, R¹⁰, and R¹¹ each independently represents hydrogen, halogen,hydroxyl, nitro, thiol, or substituted or unsubstituted C₁-C₄ alkyl,alkoxy, amino, or aryl;

each of L¹ and L² is independently present or absent, and each L¹ and L²present represents a linking atom or linking group.

The linking atom can optionally, if valency permits, have other chemicalmoieties attached. Suitable chemical moieties include hydroxy, amide,thiol, or substituted or unsubstituted alkyl, alkoxy, alkenyl, alkynyl,amino, aryl, heteroaryl, cycloalkyl, and heterocyclyl.

Embodiments of Formula B include:

where:

U represents O, S, NR, or PR;

U¹ represents N, P, As, B, NO, PO, or AsO;

Z represents O, S, SO, S(O)₂, NR, PR, CR₂, SiR₂, or BR;

Z¹ represents C or N;

Z² represents C or N; and

each R independently represents substituted or unsubstituted C₁-C₄alkyl, aryl, or heteroaryl.

Examples of complexes of Formula A and Formula B include the following:

Complexes of Formula C are represented as:

where:

R¹, R², and R³ each independently represents hydrogen, halogen,hydroxyl, nitro, thiol, or substituted or unsubstituted C₁-C₄ alkyl,alkoxy, amino, or aryl;

Y^(1a), Y^(1b), Y^(1c), Y^(1d), Y^(1e), Y^(2a), Y^(2b), Y^(2c), Y^(2d),Y^(2e), Y^(3a), Y^(3b), Y^(3c), Y^(3d), and Y^(3e) each independentlyrepresents C, N, Si, O, or S;

Ar¹, Ar², and Ar³ each independently represents an aryl or heteoraryl;

Y^(2f), valency permitting, represents N, P, N═O, P═O, NR, PR, CR, SiR,CR₂, SiR₂O, or S;

m is 1, or 3;

y is 0, 1, or 2;

the sum of m and y is 3;

each of t, u, and v is independently 0, 1, 2, 3, 4, or 5, valencypermitting;

at least one of X¹ and X² independently represents one of the followingmoieties:

and the other X¹ and X², if not one of the moieties above, isindependently absent or represents single bond, NR, PR, BR, CRR′, SiRR′,O, S, S═O, O═S═O, Se, Se═O, or O═Se═O;

R⁸, R⁹, R¹⁰, and R¹¹ each independently represents hydrogen, halogen,hydroxyl, nitro, thiol, or substituted or unsubstituted C₁-C₄ alkyl,alkoxy, amino, or aryl;

each n is independently 1, 2, 3, 4, 5, or 6, valency permitting;

each of R and R′ is independently present or absent, and each R and R′present represents substituted or unsubstituted C₁-C₄ alkyl, aryl, orheteroaryl;

each

present independently represents one of the following moieties:

Embodiments of Formula C include the following:

where:

each R⁴ and R⁵ present independently represents hydrogen, halogen,hydroxy, nitro, thiol, or substituted or unsubstituted C₁-C₄ alkyl,alkoxy, amino, or aryl;

each n is independently 1, 2, 3, 4, or 5, valency permitting;

U, U¹, and U², valency permitting, each independently represents N, P,N═O, P═O, NR, PR, CR, SiR, CR₂, SiR₂O, or S; and

R represents substituted or unsubstituted C₁-C₄ alkyl, aryl, orheteroaryl.

Disclosed are the components to be used to prepare the compositions ofthis disclosure as well as the compositions themselves to be used withinthe methods disclosed herein. These and other materials are disclosedherein, and it is understood that when combinations, subsets,interactions, groups, etc. of these materials are disclosed that whilespecific reference of each various individual and collectivecombinations and permutation of these compounds cannot be explicitlydisclosed, each is specifically contemplated and described herein. Forexample, if a particular compound is disclosed and discussed and anumber of modifications that can be made to a number of moleculesincluding the compounds are discussed, specifically contemplated is eachand every combination and permutation of the compound and themodifications that are possible unless specifically indicated to thecontrary. Thus, if a class of molecules A, B, and C is disclosed as wellas a class of molecules D, E, and F, and an example of a combinationmolecule, A-D is disclosed, then even if each is not individuallyrecited, each is individually and collectively contemplated, meaningcombinations A-E, A-F, B-D, B-F, B-F, C-D, C-E, and C-F are considereddisclosed. Likewise, any subset or combination of these is alsodisclosed. Thus, for example, the sub-group of A-E, B-F, and C-E wouldbe considered disclosed. This concept applies to all aspects of thisapplication including, but not limited to, steps in methods of makingand using the compositions disclosed herein. Thus, if there are avariety of additional steps that can be performed, it is understood thateach of these additional steps can be performed with any specificembodiment or combination of embodiments of the methods describedherein.

As referred to herein, a linking atom or linking group connects twoatoms such as, for example, an N atom and a C atom. A linking atom orlinking group is in one aspect disclosed as L¹, L², L³, etc. herein. Thelinking atom can optionally, if valency permits, have other chemicalmoieties attached. For example, in one aspect, an oxygen would not haveany other chemical groups attached as the valency is satisfied once itis bonded to two groups (e.g., N and/or C groups). In another aspect,when carbon is the linking atom, two additional chemical moieties can beattached to the carbon. Suitable chemical moieties include amino, amide,thiol, aryl, heteroaryl, cycloalkyl, and heterocyclyl moieties. The term“cyclic structure” or the like terms used herein refer to any cyclicchemical structure which includes, but is not limited to, aryl,heteroaryl, cycloalkyl, cycloalkenyl, heterocyclyl, carbene, andN-heterocyclic carbene.

As used herein, the term “substituted” is contemplated to include allpermissible substituents of organic compounds. In a broad aspect, thepermissible substituents include acyclic and cyclic, branched andunbranched, carbocyclic and heterocyclic, and aromatic and nonaromaticsubstituents of organic compounds. Illustrative substituents include,for example, those described below. The permissible substituents can beone or more and the same or different for appropriate organic compounds.For purposes of this disclosure, the heteroatoms, such as nitrogen, canhave hydrogen substituents and/or any permissible substituents oforganic compounds described herein which satisfy the valences of theheteroatoms. This disclosure is not intended to be limited in any mannerby the permissible substituents of organic compounds. Also, the terms“substitution” or “substituted with” include the implicit proviso thatsuch substitution is in accordance with permitted valence of thesubstituted atom and the substituent, and that the substitution resultsin a stable compound, e.g., a compound that does not spontaneouslyundergo transformation such as by rearrangement, cyclization,elimination, etc. It is also contemplated that, in certain aspects,unless expressly indicated to the contrary, individual substituents canbe further optionally substituted (i.e., further substituted orunsubstituted).

In defining various terms, “A¹”, “A²”, “A³”, “A⁴” and “A⁵” are usedherein as generic symbols to represent various specific substituents.These symbols can be any substituent, not limited to those disclosedherein, and when they are defined to be certain substituents in oneinstance, they can, in another instance, be defined as some othersubstituents.

The term “alkyl” as used herein is a branched or unbranched saturatedhydrocarbon group of 1 to 24 carbon atoms, such as methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl,isopentyl, s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl,dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, and the like. Thealkyl group can be cyclic or acyclic. The alkyl group can be brandied orunbranched. The alkyl group can also be substituted or unsubstituted.For example, the alkyl group can be substituted with one or more groupsincluding, but not limited to, alkyl, cycloalkyl, alkoxy, amino, ether,halide, hydroxy, nitro, silyl, sulfo-oxo, or thiol, as described herein.A “lower alkyl” group is an alkyl group containing from one to six(e.g., from one to four) carbon atoms.

Throughout the specification “alkyl” is generally used to refer to bothunsubstituted alkyl groups and substituted alkyl groups; however,substituted alkyl groups are also specifically referred to herein byidentifying the specific substituent(s) on the alkyl group. For example,the term “halogenated alkyl” or “haloalkyl” specifically refers to analkyl group that is substituted with one or more halide, e.g., fluorine,chlorine, bromine, or iodine. The term “alkoxyalkyl” specifically refersto an alkyl group that is substituted with one or more alkoxy groups, asdescribed below. The term “alkylamino” specifically refers to an alkylgroup that is substituted with one or more amino groups, as describedbelow, and the like. When “alkyl” is used in one instance and a specificterm such as “alkylalcohol” is used in another, it is not meant to implythat the term “alkyl” does not also refer to specific terms such as“alkylalcohol” and the like.

This practice is also used for other groups described herein. That is,while a term such as “cycloalkyl” refers to both unsubstituted andsubstituted cycloalkyl moieties, the substituted moieties can, inaddition, be specifically identified herein; for example, a particularsubstituted cycloalkyl can be referred to as, e.g., an“alkylcycloalkyl.” Similarly, a substituted alkoxy can be specificallyreferred to as, e.g., a “halogenated alkoxy,” a particular substitutedalkenyl can be, e.g., an “alkenylalcohol,” and the like. Again, thepractice of using a general term, such as “cycloalkyl,” and a specificterm, such as “alkylcycloalkyl,” is not meant to imply that the generalterm does not also include the specific term.

The term “cycloalkyl” as used herein is a non-aromatic carbon-based ringcomposed of at least three carbon atoms. Examples of cycloalkyl groupsinclude, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, norbornyl, and the like. The term “heterocycloalkyl” is atype of cycloalkyl group as defined above, and is included within themeaning of the term “cycloalkyl,” where at least one of the carbon atomsof the ring is replaced with a heteroatom such as, but not limited to,nitrogen, oxygen, sulfur, or phosphorus. The cycloalkyl group andheterocycloalkyl group can be substituted or unsubstituted. Thecycloalkyl group and heterocycloalkyl group can be substituted with oneor more groups including, but not limited to, alkyl, cycloalkyl, alkoxy,amino, ether, halide, hydroxy, nitro, silyl, sulfo-oxo, or thiol asdescribed herein.

The terms “alkoxy” and “alkoxyl” as used herein to refer to an alkyl orcycloalkyl group bonded through an ether linkage; that is, an “alkoxy”group can be defined as —OA¹ where A¹ is alkyl or cycloalkyl as definedabove. “Alkoxy” also includes polymers of alkoxy groups as justdescribed; that is, an alkoxy can be a polyether such as —OA¹-OA² or—OA¹-(OA²)_(a)-OA³, where “a” is an integer of from 1 to 200 and A¹, A²,and A³ are alkyl and/or cycloalkyl groups.

The term “alkenyl” as used herein is a hydrocarbon group of from 2 to 24carbon atoms with a structural formula containing at least onecarbon-carbon double bond. Asymmetric structures such as (A¹A²)C═C(A³A⁴)are intended to include both the E and Z isomers. This can be presumedin structural formulas herein wherein an asymmetric alkene is present,or it can be explicitly indicated by the bond symbol C═C. The alkenylgroup can be substituted with one or more groups including, but notlimited to, alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester,ether, halide, hydroxy, ketone, azide, nitro, silyl, sulfo-oxo, orthiol, as described herein.

The term “cycloalkenyl” as used herein is a non-aromatic carbon-basedring composed of at least three carbon atoms and containing at least onecarbon-carbon double bound, i.e., C═C. Examples of cycloalkenyl groupsinclude, but are not limited to, cyclopropenyl, cyclobutenyl,cyclopentenyl, cyclopentadienyl, cyclohexenyl cyclohexadienyl,norbornenyl, and the like. The term “heterocycloalkenyl” is a type ofcycloalkenyl group as defined above, and is included within the meaningof the term “cycloalkenyl,” where at least one of the carbon atoms ofthe ring is replaced with a heteroatom such as, but not limited to,nitrogen, oxygen, sulfur, or phosphorus. The cycloalkenyl group andheterocycloalkenyl group can be substituted or unsubstituted. Thecycloalkenyl group and heterocycloalkenyl group can be substituted withone or more groups including, but not limited to, alkyl, cycloalkyl,alkoxy, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, heteroaryl,aldehyde, amino, carboxylic acid, ester, ether, halide, hydroxy, ketone,azide, nitro, silyl, sulfo-oxo, or thiol as described herein.

The term “alkynyl” as used herein is a hydrocarbon group of 2 to 24carbon atoms with a structural formula containing at least onecarbon-carbon triple bond. The alkynyl group can be unsubstituted orsubstituted with one or more groups including, but not limited to,alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl,aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester, ether,halide, hydroxy, ketone, azide, nitro, silyl, sulfo-oxo, or thiol, asdescribed herein.

The term “cycloalkynyl” as used herein is a non-aromatic carbon-basedring composed of at least seven carbon atoms and containing at least onecarbon-carbon triple bound. Examples of cycloalkynyl groups include, butare not limited to, cycloheptynyl, cyclooctynyl, cyclononynyl, and thelike. The term “heterocycloalkynyl” is a type of cycloalkenyl group asdefined above, and is included within the meaning of the term“cycloalkynyl,” where at least one of the carbon atoms of the ring isreplaced with a heteroatom such as, but not limited to, nitrogen,oxygen, sulfur, or phosphorus. The cycloalkynyl group andheterocycloalkynyl group can be substituted or unsubstituted. Thecycloalkynyl group and heterocycloalkynyl group can be substituted withone or more groups including, but not limited to, alkyl, cycloalkyl,alkoxy, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, heteroaryl,aldehyde, amino, carboxylic acid, ester, ether, halide, hydroxy, ketone,azide, nitro, silyl, sulfo-oxo, or thiol as described herein.

The term “aryl” as used herein is a group that contains any carbon-basedaromatic group including, but not limited to, benzene, naphthalene,phenyl, biphenyl, phenoxybenzene, and the like. The term “aryl” alsoincludes “heteroaryl,” which is defined as a group that contains anaromatic group that has at least one heteroatom incorporated within thering of the aromatic group. Examples of heteroatoms include, but are notlimited to, nitrogen, oxygen, sulfur, and phosphorus. Likewise, the term“non-heteroaryl,” which is also included in the term “aryl,” defines agroup that contains an aromatic group that does not contain aheteroatom. The aryl group can be substituted or unsubstituted. The arylgroup can be substituted with one or more groups including, but notlimited to, alkyl, cycloalkyl, alkoxy alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester,ether, halide, hydroxy, ketone, azide, nitro, silyl, sulfo-oxo, or thiolas described herein. The term “biaryl” is a specific type of aryl groupand is included in the definition of “aryl.” Biaryl refers to two arylgroups that are bound together via a fused ring structure, as innaphthalene, or are attached via one or more carbon-carbon bonds, as inbiphenyl.

The term “aldehyde” as used herein is represented by the formula —C(O)H.Throughout this specification “C(O)” is a short hand notation for acarbonyl group, i.e., C═O.

The terms “amine” or “amino” as used herein are represented by theformula —NA¹A², where A¹ and A² can be, independently, hydrogen oralkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl,or heteroaryl group as described herein.

The term “alkylamino” as used herein is represented by the formula—NH-(alkyl) where alkyl is a described herein. Representative examplesinclude, but are not limited to, methylamino group, ethylamino group,propylamino group, isopropylamino group, butylamino group, isobutylaminogroup, (sec-butyl)amino group, (tert-butyl)amino group, pentylaminogroup, isopentylamino group, (tert-pentyl)amino group, hexylamino group,and the like.

The term “dialkylamino” as used herein is represented by the formula—N(-alkyl)₂ where alkyl is a described herein. Representative examplesinclude, but are not limited to, dimethylamino group, diethylaminogroup, dipropylamino group, diisopropylamino group, dibutylamino group,diisobutylamino group, di(sec-butyl)amino group, di(tert-butyl)aminogroup, dipentylamino group, diisopentylamino group, di(tert-pentyl)aminogroup, dihexylamino group, N-ethyl-N-methylamino group,N-methyl-N-propylamino group, N-ethyl-N-propylamino group and the like.

The term “carboxylic acid” as used herein is represented by the formula—C(O)OH.

The term “ester” as used herein is represented by the formula —OC(O)A¹or —C(O)OA¹, where A¹ can be alkyl, cycloalkyl, alkenyl, cycloalkenyl,alkynyl, cycloalkynyl aryl, or heteroaryl group as described herein. Theterm “polyester” as used herein is represented by the formula-(A¹O(O)C-A²-C(O)(O)_(a)— or -(A¹O(O)C-A²-OC(O))_(a)—, where A¹ and A²can be, independently, an alkyl, cycloalkyl, alkenyl, cycloalkenyl,alkynyl, cycloalkynyl, aryl, or heteroaryl group described herein and“a” is an integer from 1 to 500. “Polyester” is as the term used todescribe a group that is produced by the reaction between a compoundhaving at least two carboxylic acid groups with a compound having atleast two hydroxyl groups.

The term “ether” as used herein is represented by the formula A¹OA²,where A¹ and A² can be, independently, an alkyl, cycloalkyl, alkenyl,cycloalkenyl, alkynyl, cycloalkynyl, aryl, or heteroaryl group describedherein. The term “polyether” as used herein is represented by theformula -(A¹O-A²O)_(a)—, where A¹ and A² can be, independently, analkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl,or heteroaryl group described herein and “a” is an integer of from 1 to500. Examples of polyester groups include polyethylene oxide,polypropylene oxide, and polybutylene oxide.

The term “halide” or “halo” as used herein refers to the halogensfluorine, chlorine, bromine, and iodine.

The term “heterocyclyl,” as used herein refers to single andmulti-cyclic non-aromatic ring systems and “heteroaryl as used hereinrefers to single and multi-cyclic aromatic ring systems: in which atleast one of the ring members is other than carbon. The terms includesazetidine, dioxane, furan, imidazole, isothiazole, isoxazole,morpholine, oxazole, oxazole, including, 1,2,3-oxadiazole,1,2,5-oxadiazole and 1,3,4-oxadiazole, piperazine, piperidine, pyrazine,pyrazole, pyridazine, pyridine, pyrimidine, pyrrole, pyrrolidine,tetrahydrofuran, tetrahydropyran, tetrazine, including1,2,4,5-tetrazine, tetrazole, including 1,2,3,4-tetrazole and1,2,4,5-tetrazole, thiadiazole, including, 1,2,3-thiadiazole,1,2,5-thiadiazole, and 1,3,4-thiadiazole, thiazole, thiophene, triazine,including 1,3,5-triazine and 1,2,4-triazine, triazole, including,1,2,3-triazole, 1,3,4-triazole, and the like.

The term “hydroxyl” as used herein is represented by the formula —OH.

The term “ketone” as used herein is represented by the formula A¹C(O)A²,where A¹ and A² can be, independently, an alkyl, cycloalkyl, alkenyl,cycloalkenyl, alkynyl, cycloalkynyl, aryl, or heteroaryl group asdescribed herein.

The term “azide” as used herein is represented by the formula —N₃.

The term “nitro” as used herein is represented by the formula —NO₂.

The term “nitrile” as used herein is represented by the formula —CN.

The term “silyl” as used herein is represented by the formula —SiA¹A²A³,where A¹, A², and A³ can be, independently, hydrogen or an alkyl,cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl,or heteroaryl group as described herein.

The term “sulfo-oxo” as used herein is represented by the formulas—S(O)A¹, —S(O)₂A¹, OS(O)₂A¹, or —OS(O)₂OA¹, where A¹ can be hydrogen oran alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl,aryl, or heteroaryl group as described herein. Throughout thisspecification “S(O)” is a short hand notation for S═O. The term“sulfonyl” is used herein to refer to the sulfo-oxo group represented bythe formula —S(O)₂A¹, where A¹ can be hydrogen or an alkyl, cycloalkyl,alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, or heteroaryl groupas described herein. The term “sulfone” as used herein is represented bythe formula A¹S(O)₂A², where A¹ and A² can be, independently, an alkyl,cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, orheteroaryl group as described herein. The term “sulfoxide” as usedherein is represented by the formula A¹S(O)A², where A¹ and A² can be,independently, an alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, or heteroaryl group as described herein.

The term “thiol” as used herein is represented by the formula —SH.

“R¹,” “R²,” “R³,” “R^(n),” where n is an integer, as used herein can,independently, possess one or more of the groups listed above. Forexample, if R¹ is a straight chain alkyl group, one of the hydrogenatoms of the alkyl group can optionally be substituted with a hydroxylgroup, an alkoxy group, an alkyl group, a halide, and the like.Depending upon the groups that are selected, a first group can beincorporated within second group or, alternatively, the first group canbe pendant (i.e., attached) to the second group. For example, with thephrase “an alkyl group comprising an amino group,” the amino group canbe incorporated within the backbone of the alkyl group. Alternatively,the amino group can be attached to the backbone of the alkyl group. Thenature of the group(s) that is (are) selected will determine if thefirst group is embedded or attached to the second group.

Compounds described herein may contain “optionally substituted”moieties. In general, the term “substituted,” whether preceded by theterm “optionally” or not, means that one or more hydrogens of thedesignated moiety are replaced with a suitable substituent. Unlessotherwise indicated, an “optionally substituted” group may have asuitable substituent at each substitutable position of the group, andwhen more than one position in any given structure may be substitutedwith more than one substituent selected from a specified group, thesubstituent may be either the same or different at every position.Combinations of substituents envisioned by this disclosure arepreferably those that result in the formation of stable or chemicallyfeasible compounds. In is also contemplated that, in certain aspects,unless expressly indicated to the contrary, individual substituents canbe further optionally substituted (i.e., further substituted orunsubstituted).

In some aspects, a structure of a compound can be represented by aformula:

which is understood to be equivalent to a formula:

wherein n is typically an integer. That is, R^(n) is understood torepresent five independent substituents, R^(n(a)), R^(n(b)), R^(n(c)),R^(n(d)), R^(n(e)). By “independent substituents,” it is meant that eachR substituent can be independently defined. For example, if in oneinstance R^(n(a)) is halogen, then R^(n(b)) is not necessarily halogenin that instance.

Several references to R¹, R², R³, R⁴, R⁵, R⁶, etc. are made in chemicalstructures and moieties disclosed and described herein. Any descriptionof R¹, R², R³, R⁴, R⁵, R⁶, etc. in the specification is applicable toany structure or moiety reciting R¹, R², R³, R⁴, R⁵, R⁶, etc.respectively.

EXAMPLES

The complexes, devices, and methods described herein are not limited tospecific synthetic methods unless otherwise specified, or to particularreagents unless otherwise specified, as such can, of course, vary. It isalso to be understood that the terminology used herein is for thepurpose of describing particular aspects only and is not intended to belimiting. Although any methods and materials similar or equivalent tothose described herein can be used in the practice or testing ofcompounds of the present disclosure, example methods and materials arenow described.

Platinum and palladium complexes of Formulas A and B may be synthesizedby synthetic procedures such as those depicted below.

General procedures for the synthesis of platinum complexes of Formulas Aand B are described below, with reference to ligands L1-L4 and L7-L9above.

Procedure A: To a solution of ligand (L1, L2, L7, or L8, 1 eq) in aceticacid (0.02 M) were added K₂PtCl₄ (1.05 eq) and n-Bu₄NBr (0.1 eq). Themixture was heated to reflux for 3 days. The reaction mixture was cooledto room temperature and filtered through a short pad of silica gel. Thefiltrate was concentrated under reduced pressure. Purification by columnchromatography (hexanes:dichloromethane) gave the complexes.

Procedure B: To a solution of ligand (L3, L4, or L9, 1 eq) indimethylformamide (0.02 M) were added PtCl₂ (1.05 eq). The mixture washeated to reflux for 3 days. The reaction mixture was cooled to roomtemperature and the dimethylformamide was removed under reducedpressure. The residue was further purified by column chromatography(hexanes: dichloromethane) gave the complexes.

A general procedure for the synthesis of palladium complexes of FormulasA and B is described below, with reference to ligands L5 and L6 above.

To a solution of ligand (L5 or L6, 1 eq) in acetic acid (0.02 M) wereadded Pd(OAc)₂ (1.05 eq) and n-Bu₄NBr (0.1 eq). The mixture was heatedto reflux for 3 days. The reaction mixture was cooled to roomtemperature and filtered through a short pad of silica gel. The filtratewas concentrated under reduced pressure. Purification by columnchromatography (hexanes:dichloromethane) gave the complexes.

Iridium complexes of Formula C may be synthesized by syntheticprocedures such as those depicted below.

Opto-electronic devices that make use of organic materials are becomingincreasingly desirable for a number of reasons. Many of the materialsused to make such devices are relatively inexpensive, so organicopto-electronic devices have the potential for cost advantages overinorganic devices. In addition, the inherent properties of organicmaterials, such as their flexibility, may make them well suited forparticular applications such as fabrication on a flexible substrate.Examples of organic opto-electronic devices include OLEDs, organicphototransistors, organic photovoltaic cells, and organicphotodetectors. For OLEDs, the organic materials may have performanceadvantages over conventional materials. For example, the wavelength atwhich an organic emissive layer emits light may generally be readilytuned with appropriate dopants.

The complexes disclosed herein are suited for use in a wide variety ofdevices, including, for example, optical and electro-optical devices,including, for example, photo-absorbing devices such as solar- andphoto-sensitive devices, OLEDs, photo-emitting devices, devices capableof both photo-absorption and emission, and markers for bio-applications.

Also disclosed herein are compositions including one or more complexesdisclosed herein. The present disclosure provides light emitting devicethat include one or more complexes or compositions described herein. Thelight emitting device can be an OLED (e.g., a phosphorescent OLEDdevice). The present disclosure also provides a photovoltaic devicecomprising one or more complexes or compositions described herein.Further, the present disclosure also provides a luminescent displaydevice comprising one or more complexes or compositions describedherein.

Compounds described herein can be used in a light emitting device suchas an OLED. FIG. 1 depicts a cross-sectional view of an OLED 100. OLED100 includes substrate 102, anode 104, hole-transporting material(s)(HTL) 106, light processing material 108, electron-transportingmaterial(s) (ETL) 110, and a metal cathode layer 112. Anode 104 istypically a transparent material, such as indium tin oxide. Lightprocessing material 108 may be an emissive material (EML) including anemitter and a host.

In various aspects, any of the one or more layers depicted in FIG. 1 mayinclude indium tin oxide (ITO), poly(3,4-ethylenedioxythiophene)(PEDOT), polystyrene sulfonate (PSS),N,N′-di-1-naphthyl-N,N-diphenyl-1,1′-biphenyl-4,4′diamine (NPD),1,1-bis((di-4-tolylamino)phenyl)cyclohexane (TAPC),2,6-bis(N-carbazolyl)pyridine (mCpy),2,8-bis(diphenylphosphodibenzothiophene (PO15), LiF, Al, or acombination thereof.

Light processing material 108 may include one or more compounds of thepresent disclosure optionally together with a host material. The hostmaterial can be any suitable host material known in the art. Theemission color of an OLED is determined by the emission energy (opticalenergy gap) of the light processing material 108, which can be tuned bytiming the electronic structure of the emitting compounds, the hostmaterial, or both. Both the hole-transporting material in the HTL layer106 and the electron-transporting material(s) in the ETL layer 110 mayinclude any suitable hole-transporter known in the art.

Compounds described herein may exhibit phosphorescence. PhosphorescentOLEDs i.e., OLEDs with phosphorescent emitters) typically have higherdevice efficiencies than other OLEDs, such as fluorescent OLEDs. Lightemitting devices based on electrophosphorescent emitters are describedin more detail in WO02000/070655 to Baldo et al., which is incorporatedherein by this reference for its teaching of OLEDs, and in particularphosphorescent OLEDs.

Only a few implementations are described and illustrated. Variations,enhancements and improvements of the described implementations and otherimplementations can be made based on what is described and illustratedin this document.

What is claimed is:
 1. A complex of Formula C:

wherein: R¹, R², and R³ each independently represents hydrogen, halogen,hydroxyl, nitro, thiol, or substituted or unsubstituted C₁-C₄ alkyl,alkoxy, amino, or aryl; Y^(1a), Y^(1b), Y^(1c), Y^(1d), Y^(1e), Y^(2a),Y^(2b), Y^(2c), Y^(2d), Y^(2e), Y^(3a), Y^(3b), Y^(3c), Y^(3d), andY^(3e) each independently represents C, N, Si, O, or S; Ar¹, Ar², andAr³ each independently represents an aryl or heteoraryl; Y^(2f), valencypermitting, represents N, P, N═O, P═O, NR, PR, CR, SiR, CR₂, SiR₂, O, orS; m is 1, 2, or 3; y is 0, 1, or 2; the sum of m and y is 3; each of t,u, and v is independently 0, 1, 2, 3, 4, or 5, valency permitting; atleast one of X1 and X2 independently represents one of the followingmoieties:

and the other X¹ and X², if not one of the moieties above, isindependently absent or represents single bond, NR, PR, BR, CRR′, SiRR′,O, S, S═O, O═S═O, Se, Se═O, or O═Se═O; R⁸, R⁹, R¹⁰, and R¹¹ eachindependently represents hydrogen, halogen, hydroxyl nitro, thiol, orsubstituted or unsubstituted C₁-C₄ alkyl, alkoxy, amino, or aryl; each nis independently 1, 2, 3, 4, 5, or 6, valency permitting; each of R andR′ is independently present or absent, and each R and R′ presentrepresents substituted or unsubstituted C₁-C₄ alkyl, aryl, orheteroaryl; and each

present independently represents one of the following moieties:


2. The complex of claim 1, represented by one of the followingstructures:

where: each R⁴ and R⁵ present independently represents hydrogen,halogen, hydroxy, nitro, thiol, or substituted or unsubstituted C₁-C₄alkyl, alkoxy, amino, or aryl; each n is independently 1, 2, 3, 4, or 5,valency permitting; U, U¹, and U², valency permitting, eachindependently represents N, P, N═O, P═O, NR, PR, CR, SiR, CR₂, SiR₂, O,or S; and R represents substituted or unsubstituted C₁-C₄ alkyl, aryl,or heteroaryl.
 3. A light emitting device comprising the complex ofclaim
 1. 4. An organic light emitting device comprising the complex ofclaim
 1. 5. The organic light emitting device of claim 4, wherein thedevice is a phosphorescent organic light emitting device.
 6. Aphotovoltaic device comprising the complex of claim
 1. 7. A luminescentdisplay device comprising the complex of claim 1.